Cam



.Dec. 17, 1957 w. "r. RATLIFF CAM Filed June 3, 1954 mlllllllllllll ATTORNEYS r W/Ll/AIM z m TZ/FF mvmron United States Patent CAM William T. Ratliff, Oklahoma City, Okla.

Application June 3, 1954, Serial No. 434,275

1 Claim. (Cl. 123--90) This invention relates to a new type of cam and more particularly to a cam for cam shafts for internal combustion engines.

It is an object of this invention to provide an improved type of cam for internal combustion engines which is cylindrical in form with a segment removed from the outer circumference thereof so that in operation, as the tappet follows the bearing surface on such outer circumference of the cam, the tappet will glide into the segmental portion thus providing the reciprocal motion for opening and closing the valve as the valve glides into and out of the segment. This type of cam is designed for use with an outwardly opening valve and to provide for quicker and fuller opening of the valve.

It is another object of this invention to provide an improved cam of the kind to be more particularly described hereinafter which will provide for the quicker and fuller opening of the valve with no more friction than is encountered in the operation of cams now in use for a somewhat similar purpose.

Other .and further objects and advantages of the invention will be hereinafter described and the novel features thereof defined in the appended claim.

In the drawings:

Fig. 1 is a side elevation, partly broken away and partly in section of an internal combustion engine on which the cam of my invention is used.

Fig, 2 is a perspective view of the cam and cam shaft removed from the engine.

Heretofore it may have been the custom in the industry to employ a cam for opening and closing the valve on one end of the cylinder of an internal combustion engine. It is the primary purpose of this invention to provide an improved cam for use in an internal combustion engine whereby a quicker and fuller opening of the valve may be achieved than is encountered in the operation of cams now in use.

Referring more specifically to the drawings the cam of my invention is designated by the reference numeral in an internal combustion engine 11.

Pistons 14 are reciprocal in the cylinders 12 having a piston rod 15 pivotally connected thereto and one end of the piston rod remote from the piston is pivotally connected to a crank 16 on a drive shaft 17.

There is provided a valve 18 between the upper end or combustion end of the cylinder 12 and its associated head 19. A gas chamber is fixed to or formed on the engine head 19 and a rocker arm 21 is pivotally connected intermediate the length thereof to a support extending upwardly from the head 19.

2,8 16,532 Patented Dec. 1 7, 1 957 fiice One end of the rocker arm 21 engages with the valve 18 for actually closing the valve against the tension of a resilient means carried by the internal combustion engine.

The end of the rocker arm 21 remote from the valve 18 is engaged with one end of a lift rod 22 which has a tappet 24 at its other lower end.

The tappet is engageable with the surface of the cam 10 there being a substantially V-shaped notch 25 in the periphery of the cam 10. The cam has a smooth periphery 26 adjacent the edges of the V-shaped notch 25.

The side walls of the V-shaped cut out notch 25 have reversely curved side walls 27 therein with a concave apex 28 at the apex of the V-shaped cut out.

The cam 10 is rotated by a cam shaft 29 Which in turn is actuated in a substantially conventional manner in its relation to the drive shaft 17. In the operation of the internal combustion engine having my improved cam therein the engine is caused to be actuated in a conventional manner as the cam shaft 29 is rotated in its proper relation to the rotation of the drive shaft 17 by means not shown in the drawings or applicable to this invention. The valve 18 may be or will be operated in timed relation to the rotation of the cam shaft 29 for opening and closing the valve 18. With this improved cam in the internal combustion engine the actuation of the valve will be quicker and the valve will be moved to a fuller opening than in conventional internal combustion engines. The valve 18 may be to an intake manifold or to an exhaust manifold as in either case the valve will be actuated in the same manner and substantially for a similar purpose.

While the specific details of one embodiment of this invention have been herein shown and described, the invention is not confined thereto as changes and alterations may be made without departing from the spirit and scope thereof as defined in the appended claim.

I claim:

In a cam shaft for an internal combustion engine, a cam fixed to said shaft comprising a disc-shaped member having an axial opening in which said shaft is secured, said disc having a cutout in the periphery thereof extending inwardly toward the center, said cutout being of generally U-shape with a concave inner apex and with outwardly divergent convex surfaces merging with said concave apex, the radii passing through the outer ends of said cutout being disposed on an acute angle whereby to provide for quick movement of the valve lift to valve opening or closing position.

References Cited in the file of this patent UNITED STATES PATENTS 418,418 Nash Dec. 31, 1889 599,496 Fraser Feb. 22, 1898 674,709 Rourk May 21, 1901 1,763,563 Ostberg June 10, 1930 1,784,421 Eslinger Dec. 9, 1930 2,032,542 Mantle Mar. 3, 1936 2,049,253 Ely July 28, 1936 2,117,551 Forkois et .al. May 17, 1938 2,391,972 Huiford et al. Jan. 1, 1946 FOREIGN PATENTS 5,690 Great Britain Mar. 7, 1911 

